Chainsaw Repair

    Ummmmmmm, I'm not a hundred percent sure either way, but I do know for sure that the 662/667/670/673/675/680 all have a 38mm stroke. The 690/694/603 have a 42mm stroke. How could the cases be the same with a 4mm stroke difference.
   Another interesting fact I have found on the 662/667, is that they share the same cylinder base bolt pattern as a 7900 Dolmar, as I used my Dolmar base plate to turn the jug.

I'm 100% sure they are different. I have them all and have torn them all down and built them up. The crankcases and all the parts are completely different on the 662/667 as compared to the 680/690/603 saws. The 665/675/681 are on the same case as each other too, also the same as the Dolmar 7900, but different then the older Solo's...lol it gets kinda confusing but when you have them all in front of you it makes sense.

Strokes can easily be changed with different rod lengths or different cranks. I've taken a 680 jug and put it on a 603 for the longer stroke and vice versa, all the parts interchange with those saws besides the stroke.